RE: [boost] Re: Spirit question...

From: Hartmut Kaiser (hartmutkaiser_at_[hidden])
Date: 2003-08-27 01:44:20

David B. Held wrote:

> The moral being:
> 
>     Using anychar_p all by itself is usually a Bad Thing(TM)
> 
> That's because it's like the langoliers--it eats everything 
> up. You usually want to say what it shouldn't eat up by 
> subtracting the terminating character from the parser.  I 
> think this is a Spirit FAQ.

This isn't correct, sorry. 

The anychar_p parser used by itself isn't a bad thing, because it eats
up only _one_ arbitrary character/token from the input stream, which may
be very useful. The problematic part is the kleene_star operator, which
requires some additional attention, because it "repeats" the attached
parser zero or more times. So the kleene_star in conjunction with the
anychar_p will eat up all your input sequence, regardless of what in
contains. But this may happen with other attached parsers too.

Regards Hartmut

BTW: this kleene_star behaviour _is_ a FAQ, see here:
http://www.boost.org/libs/spirit/doc/faq.html#kleene_star